mismatched flywheels

I can't figure this out

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panfreak
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mismatched flywheels

#1

Post by panfreak » Fri Aug 09, 2019 5:24 pm

So I have a disassembled 1973 motor and the 4-1/4" stroke flywheel assembly is weird. Looks to me like an evo left wheel mated to a shovel right? I did some internet research to try identifying them by the stamped numbers but it's confusing. Can someone just have a look and confirm what exactly I have here? And if so, after fitting rod bearings and truing them up, can I install in the 73 cases like normal or am I going to run into issues with compensator and/or other stock year parts? If I were to guess I'd say the original builder just wanted a lighter left wheel which is ok by me but I don't want a headache trying to buy parts for a dogs breakfast of years. If sprocket shaft is same length etc and motor will go back together like it doesn't know any difference then I'll keep it.
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Re: mismatched flywheels

#2

Post by Frankenstein » Sun Aug 11, 2019 2:44 pm

Did some research on your questions, waited awhile for someone smarter than I to respond, but that didn't happen.
Seems to me that I'd give it a go. Splines, shaft diameter, etc didn't change on the drive side through the shovel years into the early evo stuff. V-Twin does list a couple of longer 1/4", 1/2" for late 80 shovels, maybe big belt drive options?
I'd do a quick mockup with the inner timken in place and the left flywheel into the case to just make sure your driveside mainshaft is roughly where it ought to be. There's some latitude anyway, the factory had varying spacers to make up minor chain alignment issues.
I'd say it's pretty likely to be a fit, just double check stuff for reassurance.
DD

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Re: mismatched flywheels

#3

Post by RUBONE » Sun Aug 11, 2019 11:58 pm

Do not confuse casting numbers with part numbers,(and the cast in number on either side will differ considerably from the other side). While they may be close, they are not the same. A '73 never came stock with a 4-1/4 wheel set so they have obviously been changed. The wheels look perfectly normal to me, what is your concern?

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Re: mismatched flywheels

#4

Post by panfreak » Mon Aug 12, 2019 3:16 pm

My only worry is having an engine that's been put together like the caddy from Johnny Cash's "one piece at a time". I think you two have essentially answered my question which I appreciate because it was borderline not worthy of a post.

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Re: mismatched flywheels

#5

Post by RooDog » Mon Aug 12, 2019 10:32 pm

As an aside question: The left side, sprocket shaft side, looks to be one piece. Didn't Harley make some later "three piece" crank assemblies where the each flywheel and shaft were forged together, with the crank pin being the third piece? And didn't Harley also build some left hand wheels with the shaft nutted in place, interference fitted taper but no key? And isn't all this foolishness common in Evos?
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Re: mismatched flywheels

#6

Post by kitabel » Tue Aug 13, 2019 12:44 am

Yes, and if that's true they should mate if the pin is 1981-* "commonized".
What's troubling is: does it change the sprocket position and chain row distance?
I'm afraid to guess, not enough personal experience.

W/r/t/ not worthy of a post: my own standard: if it's important to you, and you've already done research on your own and can't figure it out, it's worth my time to look at it.

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Re: mismatched flywheels

#7

Post by Frankenstein » Tue Aug 13, 2019 12:14 pm

Good call Roo Dog, sure looks to be a one piece flywheel/shaft. Doesn't mean it's not worth a try. Shaft length is only thing that might bother, but for the effort of pressing on a roller bearing in the drive shaft, you can answer all your questions. I'm beginning to suspect that they're Evo flywheels, which isn't a bad thing. You must have or know someone who has a used bearing you can play with, right?
DD

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Re: mismatched flywheels

#8

Post by RooDog » Tue Aug 13, 2019 1:43 pm

A sure sign that they may be Evo is that both the L anf R wheels are the same thickness and weight. Shovelhead wheels have a heavy and a light, right side, wheel. All $&$ stroker wheels are two light wheels, T&O uses one light and one heavy, like stock, in their kits. I built my 74" Panny engine with two right side wheels, back in 1968, and had it rebalanced. Still running like that all these years later.
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Re: mismatched flywheels

#9

Post by Andygears » Wed Aug 14, 2019 12:12 am

A trick I learned for the timken main bearing set: a 1 inch micrometer will just fit into the left crankcase hole with the thick snap ring in place, on a motor in for renewal ( not catastrophic fail) measure the thickness of the snap ring, then at the counter when you buy the "timken set", open the package and measure the new snap ring, it acts as a spacer to set the bearings, a set with the same thickness snap ring can be used with the old snap ring eliminating the pain in the ass removal. I also heard they only make a couple different thicknesses.

My two cents
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Re: mismatched flywheels

#10

Post by RUBONE » Wed Aug 14, 2019 2:09 am

Since the snap ring was brought up, if you do replace it make sure the open ends face up so as not to block the oil hole. The same oil hole is used for removal, move the snap ring to where one end covers the hole and use a long drift to push that end down to start the removal process.

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Re: mismatched flywheels

#11

Post by Frankenstein » Thu Aug 15, 2019 12:15 pm

RooDog; Tricky, Nothing like a set of Shovel wheels to send you rolling down the road! An Old dog who photoshops, neat pic.
DD

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Re: mismatched flywheels

#12

Post by panfreak » Thu Aug 15, 2019 8:50 pm

This is all good info, thanks everyone. The sprocket shaft is one with the wheel. I've turned down a lot of heavy left wheels to "match" the right one for a lighter bottom end, I just assumed(?) maybe someone matched an evo left to a shovel right to accomplish this when I initially looked through the pile of parts I was given, but not having experience trying to do just that (or knowing if that's possible for that matter), I needed to ask the big question "what the hell have I got here" cause searching the net was even more confusing. Now that I'm working on getting it back together I began coming up with all these questions of mismatched parts and what problems if any may arise. The cases are for sure 1973, and if I put new crank pin in the flywheels, fit bearings then true, I just want to know whether or not I can throw this set in there. The stroke, jugs and heads I have will give me an 80", essentially I'm concerned about pinion and sprocket shafts in a '73 case. Spacing on the sprocket side is easy, but will I need to run a different year cone to match the pinion shaft for example? What years did this particular pinion shaft span? I cannot say with 100% certainty that the motor I got had them in it when it was together and running, hence my concern, I think my last question will put a close to this topic for me, thank you again for your patience.

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